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本文探讨了一种处理动态工作流系统变更的方法。首先介绍了几种常见的处理工作流变更的方法.然后提出了一个对当前工作流的修改进行合并的有效处理算法.最后给出了一个实例以验证算法的有效性。 相似文献
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本文探讨了一种处理工作流动态变更的方法.首先介绍了几种常见的处理工作流变更的方法.然后提出了一种工作流实例迁移算法.算法根据工作流实例迁移后有向边的值来确定该实例能否正确迁移.最后给出了一个实例以验证算法的有效性. 相似文献
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代价敏感属性选择问题的目的是通过权衡测试代价和误分类代价,得到一个具有最小总代价的属性子集。目前,多数代价敏感属性选择方法只考虑误分类代价固定不变的情况,不能较好地解决类分布不均衡等问题。而在大规模数据集上,算法效率不理想也是代价敏感属性选择的主要问题之一。针对这些问题,以总代价最小为目标,设计了一种新的动态误分类代价机制。结合分治思想,根据数据集规模按列自适应拆分各数据集。基于动态误分类代价重新定义最小代价属性选择问题,提出了动态误分类代价下的代价敏感属性选择分治算法。通过实验表明,该算法能在提高效率的同时获得最优误分类代价,从而保证所得属性子集的总代价最小。 相似文献
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为提高工作流的柔性,解决工作流模型变更引起的流程实例迁移问题,提出了即时变更处理方法.该方法基于Petri网模型,用关系矩阵定义节点路由,用状态标识矩阵描述流程实例执行状态,通过变更处理算法查找可越过节点和迁移节点,实现了流程实例的即时变更.最后以更改签收流程为例,验证了文中方法的可行性. 相似文献
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基于最小代价的多分类器动态集成 总被引:2,自引:0,他引:2
本文提出一种基于最小代价准则的分类器动态集成方法.与一般方法不同,动态集成是根据“性能预测特征”,动态地为每一样本选择最适合的一组分类器进行集成.该选择基于使误识代价与时间代价最小化的准则,改变代价函数的定义可以方便地达到识别率与识别速度之间的不同折衷.本文中提出了两种分类器动态集成的方法,并介绍了在联机手写汉字识别中的具体应用.在实验中使了3个分类器进行动态集成,因此,得到7种分类组合.在预先定义的代价意义下,我们比较了动态集成方法和其它7种固定方法的性能.实验结果证明了动态集成方法的高灵活性、实用性和提高系统综合性能的能力. 相似文献
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针对目前工作流管理系统在描述能力和动态修改上存在的不足,提出一种基于构件的动态修改策略。该策略引入新的建模元素和动态修改的体系结构,阐述了工作流的组合策略、修改方法和移交策略;最后论述了这种策略的优越性、可行性和正确性。 相似文献
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主要研究了资源分配基数,提出了一种新的基于选择消费代价网格资源分配算法。提出的方法首先采用模糊基数建立一个消费代价函数模型,给出了网络中带权值的多参数消费代价函数。实例验证表明,当用户需要从系统中获得资源时,采用该方法在网格规模非常大而且计算量较小的情况下,选择代价最小的方法给用户使用来分配资源,具有一定的实际应用价值。 相似文献
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Today's workflow management systems (WFMSs) are only applicable in a secure and safe manner if the business process (BP) to be supported is well-structured and there is no need for ad hoc deviations at run-time. As only few BPs are static in this sense, this significantly limits the applicability of current workflow (WF) technology. On the other hand, to support dynamic deviations from premodeled task sequences must not mean that the responsibility for the avoidance of consistency problems and run-time errors is now completely shifted to the (naive) end user. In this paper we present a formal foundation for the support of dynamic structural changes of running WF instances. Based upon a formal WF model (ADEPT), we define a complete and minimal set of change operations (ADEPTflex) that support users in modifying the structure of a running WF, while maintaining its (structural) correctness and consistency. The correctness properties defined by ADEPT are used to determine whether a specific change can be applied to a given WF instance or not. If these properties are violated, the change is either rejected or the correctness must be restored by handling the exceptions resulting from the change. We discuss basic issues with respect to the management of changes and the undoing of temporary changes at the instance level. Recently we have started the design and implementation of ADEPTworkflow, the ADEPT workflow engine, which will make use of the change facilities presented in this paper. 相似文献
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Exterminating the Dynamic Change Bug: A Concrete Approach to Support Workflow Change 总被引:14,自引:1,他引:13
W.M.P. van der Aalst 《Information Systems Frontiers》2001,3(3):297-317
Adaptability has become one of the major research topics in the area of workflow management. Today's workflow management systems have problems dealing with both ad-hoc changes and evolutionary changes. As a result, the workflow management system is not used to support dynamically changing workflow processes or the workflow process is supported in a rigid manner, i.e., changes are not allowed or handled outside of the workflow management system. In this paper, we focus on a notorious problem caused by workflow change: the dynamic change bug (Ellis et al.; Proceedings of the Conference on Organizational Computing Systems, Milpitas, California, ACM SIGOIS, ACM Press, New York, 1995, pp. 10–21). The dynamic change bug refers to errors introduced by migrating a case (i.e., a process instance) from the old process definition to the new one. A transfer from the old process to the new process can lead to duplication of work, skipping of tasks, deadlocks, and livelocks. This paper describes an approach for calculating a safe change region. If a case is in such a change region, the transfer is postponed. 相似文献
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支持动态可变并具备灵活性是人们在实际应用中对工作流管理系统提出的新要求,已有的相关研究工作都集中在对工作流中发生变化的某个具体问题上.提出了支持动态特性的工作流过程元模型,可以为动态过程模型的设计提供指导.从时间和工作流组成的过程级别两个角度分析了其动态特性的表现,扩展了工作流管理联盟的工作流元模型.扩展后的过程元模型在工作流的建立阶段力求将动态特性进行描述和定义,在工作流执行阶段可以根据已定义的动态属性,处理过程的变化情况.基于该元模型,工作流管理系统既具有灵活性,又有利于变化控制操作. 相似文献
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首先介绍了工作流异常处理的体系结构,然后详细介绍了异常处理在流程建模中的描述方式和异常处理的四个基本方法:事务特性与程序设计结合法、知识库法、ECA规则法和工作流进化法。最后展望了工作流异常处理的未来发展方向。 相似文献
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A Light Workflow Management System Using Simple Process Models 总被引:7,自引:0,他引:7
Alessandra Agostini Giorgio de Michelis 《Computer Supported Cooperative Work (CSCW)》2000,9(3-4):335-363
Workflow management systems are considereda hot technology. Nevertheless, up to now they havenot had the diffusion other packages such asproductivity tools, E-mail systems and groupwareplatforms have. We believe that this fact is due tothe many limitations of current workflow technology(weak support for changes; complex exception handlingmechanisms; limited openness to and integrability withother system components;...) and that radically newworkflow management systems should be designed anddeveloped in order to offer adequate products to themarket. In this paper, we outline the main innovativefeatures of the workflow management component of theMilano system making it highly flexible and adaptable.Particular attention is paid to its modellingframework, which is based on a class of net systemswell supported by efficient algorithms, and to theservices it offers to both workflow designers andactors. The most relevant aspects of the MILANOworkflow management system are also illustratedthrough a realistic example. 相似文献
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一个支持动态变化的工作流管理系统 总被引:6,自引:0,他引:6
随着工作流技术得到越来越广泛的应用,人们对工作流管理系统提出了新的要求,要求系统能够具有动态变化和灵活的处理能力.以便有效地支持今天所处的具有动态的、不确定的和易于出错的协同工作环境.文章扩展了工作流管理联盟给出的工作流模型,提出了动态工作流模型,并以此模型为指导.设计实现了具有动态灵活能力的工作流管理系统TH—workflow,该系统将工作流的功能特性划分为三个层次,即应用层、功能层和实现层.在不同的层次上实现了工作流的基本服务和动态灵活的控制功能. 相似文献
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工作流异常处理的形式描述 总被引:14,自引:0,他引:14
异常处理是工作流执行中要解决的主要问题之一,清楚地描述异常处理的过程是最终得到实现的基础。Petri-net对工作流的描述适合于对过程定义进行正确性验证和评价,但描述各种不同条件下的处理策略却很繁琐,采用了一种直观的描述方法对异常处理过程中的元素,即活动、异常处理策略以及处理措施进行了形式化描述,特别是对不同处理策略下的处理过程进行了描述。结合消息机制,分析了一个异常事件出现时,如何处理一个活动实例产生的中间数据,并对事务处理和异常处理的补偿策略进行了比较。描述方法为编码实现提供了很大的方便。 相似文献
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工作流系统中的一种异常处理机制 总被引:1,自引:0,他引:1
文中通过对工作流系统可能出现的异常情况进行较详细的分析,提出了利用规则库进行异常处理的模型,并对异常处理规则的数据结构进行了较深入的探讨。 相似文献
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Gert Faustmann 《Computer Supported Cooperative Work (CSCW)》2000,9(3-4):413-434
The advantages of today's processmanagement, such as efficiency and quality aspects,are achieved by enforcing detailed models of workprocesses. However, real world processes can beplanned to a limited degree only and sometimes plannedparts of the process must be changed,creating a need for additional, unforeseen activities.This paper suggests an approach that configuresparts of a detailed process model with differentsupport strategies. The explicit modelling of thesesupport strategies allows them to be changed ifdemanded by the situation. When enacting such aprocess model it is then possible to vary the degreeto which the model determines the work ofindividuals. The concept is based on an earlierenactment concept which allowed workers to freelychoose methods for their tasks according to thesituation. Besides the incorporation of differentsupport strategies, the extended enactment strategygives workers the opportunity to negotiate aboutchanging a currently too restrictive support strategy,giving scope for deviations from the plannedprocess where additional actions are required. 相似文献